lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

ARM: OMAP: Fix McBSP spin_lock deadlock

Browse Source 
A spin_lock deadlock will occur when omap_mcbsp_request() is invoked.

omap_mcbsp_request()
\- clk_enable(mcbsp->clk)         [takes and holds clockfw_lock]
    \- omap2_clk_enable()
       \- _omap2_clk_enable()
           \- omap_mcbsp_clk_enable()
              \- clk_enable(child clock)   [tries for clockfw_lock again]

mcbsp_clk is a virtual clock and it comprises several child clocks. when
enable mcbsp_clk in omap_mcbsp_request(), the enable function of mcbsp_clk
will enable its child clocks, then the deadlock occurs.

The solution is to remove the virtual clock and enable these child clocks in
omap_mcbsp_request() directly.

Signed-off-by: Stanley.Miao <stanley.miao@windriver.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
This commit is contained in:
Stanley.Miao
2009-01-29 08:57:12 -08:00
committed by Tony Lindgren
parent 18e352e4a7
commit 06151158f2
4 changed files with 78 additions and 223 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
arch/arm/plat-omap/include/mach/mcbsp.h
View File

@@ -344,7 +344,8 @@ struct omap_mcbsp_platform_data {
u8 dma_rx_sync, dma_tx_sync;
u16 rx_irq, tx_irq;
struct omap_mcbsp_ops *ops;
char const *clk_name;
char const **clk_names;
int num_clks;
};
struct omap_mcbsp {
@@ -376,7 +377,8 @@ struct omap_mcbsp {
/* Protect the field .free, while checking if the mcbsp is in use */
spinlock_t lock;
struct omap_mcbsp_platform_data *pdata;
struct clk *clk;
struct clk **clks;
int num_clks;
};
extern struct omap_mcbsp **mcbsp_ptr;
extern int omap_mcbsp_count;